Process for manufacturing aluminum compounds



PROCESS FOR MANUFACTURING ALUMINUM COMPOUNDS Herbert R. Appell,Riverside, 111., assignor to Universal Oil Products Company, DesPlaiues, III., a corporation 'of Delaware 7 No Drawing. ApplicationSeptember 27, 1954, I Serial No. 458,711

" 8Claims. CI. 23-50 This application is a continuation-in-part of mycopending applicationSerial No. 380,103 filed September 14, 1953, nowabandoned.

This invention relates to an improved method of preparing aluminumcompounds. It more specifically relates to a method of preparinghydroxyl substituted aluminum salts from an acid salt of aluminum.

Recently commercial uses of many of the hydroxyl substituted aluminumsalts have been developed. Aluminum hydroxychlorides became importantstarting mate rials in the manufacture of catalysts and aluminumhydroxychlorides are also being directly used as antiperspirants. Theprocess of this invention is particularly suitable for the manufactureof aluminum hydroxychlorides such as aluminum dihydroxychloride andaluminum hydroxydichloride which are represented by the formulaAl(OH)2C1 and AlClzOH respectively. basic salts of aluminum other basicaluminum salts such as basic aluminum sulfate and basic aluminum nitratemaybe prepared. These compounds may be represented by the formulasAl(SO4)OH and Al(NO3)2OH or Al(NO3)(OH)z respectively. Modifications ofthe sulfate form are dialuminum tetrahydroxysulfate and trialuminumpentahydroxydisulfate. The process of this invention may be used as abasic step in preparing these aluminum salts.

In one embodiment the present invention relates to a method of preparinga hydroxyl substituted aluminum salt which comprises contacting asolution of a salt of aluminum with an anion exchange material in thehydroxyl form and recovering the effluent.

In a specific embodiment the present invention relates to a method ofproducing aluminum hydroxychloride which comprises contacting a solutionof aluminum chloride with an anion exchange material in the hydroxylform and recovering the efiluent.

The salt of aluminum that is used as a starting material in the processof this invention is preferably an acid salt such as aluminum chloride,aluminum nitrate, aluminum sulfate, aluminum fluoride, etc., that is,salts which may be formed by the reaction of aluminum and a strong acid.The preferred acid salts are water soluble. It is preferred that anaqueous solution be used, however, other solvents may be used butgenerally the aqueous solutions show great advantages, and for thisreason they are preferred. In some cases a monohydroxyl substitutedaluminum salt may be used as a starting material which is converted tothe dihydroxyl substituted aluminum salt according to the process ofthis invention. For example, aluminum hydroxydichloride may be used toproduce aluminum dihydroxychloride. In the interest of simplicity thepresent specifications will be directed primarily to the manufacture ofaluminum hydroxychlorides. However, it is understood that the novelfeatures of the present invention may be employed for the manufacture ofother hydroxyl substituted aluminum salts herein mentioned. It isunderstood that when these other hydroxyl substituted aluminum salts areto be Besides these 2,791,486 Patented May 7-, 1957 manufactured, thecorresponding acid salts will be employed. As for example, in themanufacture of aluminum hydroxynitrate, aluminum nitrate will beemployed, etc. Similarly the novel features of the present inventionmaybe employed for the manufacture of 'hydroxy substituted basicaluminum salts from aluminum organic salts such as aluminum acetate,aluminum butyrate, etc.

It will be noted that in accordance with the present invention asolution of a salt of aluminum is contacted with an anion exchangematerial in the hydroxyl'form, and as hereinbefore mentioned, it ispreferred that an aqueous solution of the salt be used.

Any suitable solid anion exchange material that can be converted to thehydroxyl form and that maybe readily regenerated by the use of analkaline reagent may be used in the process of my invention, however,weak and moderately basic anion exchange resins are preferred with thestronger anion exchange resins being less preferred. Examples of anionexchange resins that may be used in my process are those resins whichare formed by the polymerization of an aromatic amine and formalde: hydeor a polyamine, a phenol, and formaldehyde. 7 An, example of a resin inthis group is a cross-linked, polystyrene, polyamine anion exchanger.Other suitable resins may be prepared by the nitration and subsequentreduction of a styrene-divinylbenzene copolymer. Among the commerciallyknown resins that may be employed there may be mentioned Amberlite IR4B,Amberlite IR- 45, De 'Acidite, Duolite A-2, Ionac A-300, and Wofatit M.

These anion exchange resins may be present in various physical formssuch as powder or chips and a particularly suitable form is thespheroidal form. The anion exchange materials to be used are waterinsoluble, that is substantially water insoluble, and. are in the solidform. One of the. disc'overiesof my invention is, in fact,.that solidanion exchange materials may be used to prepare the compounds of thisinvention. By the process of my invention these hydroxyl substitutedbasic aluminum salts are produced more cheaply and easily thanheretofore possible.

Generally speaking, the anion exchange materials that are preferred canbe regenerated by treatment with an alkaline solution and-in theresulting hydroxylated condition they will substitute hydroxyl ions forthe anions that are present in the aluminum salt. The anion exchangematerials have satisfactory physical stability especially in referenceto temperature so that they may be used at temperatures from thefreezing point of the solution up to the boiling point of the solution,however, each ion exchange material is specific in reference to themaximum temperature at which it is stable. At the higher temperaturesthe rate of ion exchange is usually much more rapid, however, roomtemperatures are generally very satisfactory.

The main requirement of the anion exchange resin is that it shouldreplace only a portion of the anion originally in the aluminum salt by ahydroxyl group (OH group) and for this reason, as hereinbeforementioned, weakly basic and mildly basic anion exchange resins arepreferred. The basic resin after use may be regenerated by an alkalinereagent such as sodium carbonate, sodium hydroxide, potassium carbonate,potassium hydroxide, ammonium hydroxide, etc., in fact almost anyalkaline reagent is satisfactory.

The ratio of aluminum to hydroxyl ion in the hydroxyl substituted basicaluminum salt that is formed may be controlled in several ways,especially by adjusting the concentration of the salt solution, theamount of anion exchange resin, the contact time, and the strength ofthe anion exchange resin. For example, starting with aluminum chlorideit is possible to substitute one hydroxyl for T i 2,791,486 i one of thechloride ions or two chloride ions may be exchanged for the hydroxylions. Using a weak solution of aluminum chloride at low spacevelocities, that is contacting the solution of aluminum chloride withthe anion exchange material for a long length of time using a moderatelybasic anion exchange material, the product will contain a large amountof aluminum dihydroxychloride. Similarly, using a highly concentratedsolution of aluminum chloride and subjecting the same to contact with aweak anion exchange material for a short period of time the product willconsist mainly of the less substituted basic salt, that is aluminumhydroxydichloride. As hereinbefore mentioned, higher temperatures alsogenerally favor higher exchange rates.

The invention may be practiced in a batch wise or continuous fashion. Inthe batch method the reactants and ion exchange material are placed in asuitable vessel and contacted, and the product subsequently separated byfiltration or other suitable means. In the continuous process the ionexchange material is placed in a suitable reaction vessel and thesolution is passed continuously therethrough in either upward ordownward flow.

The process of the present invention may be practiced in any suitabletype of equipment wherein the solution and anion exchange material areintimately contacted, and mixing devices may be used to insure uniformand thorough contacting.

The hydroxyl substituted salts differ in many physical properties fromthe salts from which they were prepared and the hydroxyl substitutedsalts may be separated from the solution in any suitable manner such asby crystallization, solvent extraction, selective absorption, etc.

The following example is given to illustrate the novelty and utility ofthe process of my invention but not with the intention of undulylimiting the generally broad scope of the invention.

Example 30 grams of aluminum chloride hexahydrate were dissolved in 70grams of water. 25 ml. of this solution were then passed through a 5 ml.bed of commercial IR-45 Amberlite anion exchange resin which is a weaklybasic cross-linked polystyrene, polyamine anion exchange resin. Thesolution and the anion exchange resin were maintained at roomtemperature and the solution was passed through in approximately thirtyminutes. The solution entering the anion exchange resin had a pH of 1.4and the exit stream had a pH of 3.9. The product was analyzed and showedan appreciable conversion of the aluminum chloride to aluminumhydroxychloride.

I claim as my invention:

1. A method of preparing a hydroxyl substituted basic aluminum saltwhich comprises contacting a solution of a salt of aluminum with aweakly basic, water insoluble anion exchange resin in the hydroxyl formand recovering the efiluent.

2. The method of claim 1 further characterized in that said anionexchange resin is regeneratable by an alkaline reagent.

3. A method of preparing an aluminum salt containing at least onehydroxyl group which comprises contacting a solution of an acid salt ofaluminum with a weakly basic, water insoluble anion exchange resin andrecovering the efiiuent.

4. A method of producing aluminum hydroxychloride which comprisescontacting a solution of aluminum chloride with a weakly basic, waterinsoluble anion exchange resin in the hydroxyl from and recovering theefiluent.

5. A method of producing aluminum hydroxysulfate which comprisescontacting a solution of aluminum sulfate with a weakly basic, waterinsoluble anion exchange resin in the hydroxyl form and recovering theefliuent.

6. A method of preparing an aluminum hydroxynitrate which comprisescontacting a solution of aluminum nitrate with a weakly basic, waterinsoluble anion exchange resin in the hydroxyl form and recovering theefiiuent.

7. A method of preparing dihydroxyl substituted basic aluminum saltswhich comprises contacting a solution of a salt of aluminum selectedfrom the group consisting of acid salts of aluminum and mono-hydroxylsubstituted aluminum salts and mixtures thereof with a Weakly basic,water insoluble anion exchange resin in the hydroxyl form and recoveringthe'efliuent.

8. A method of producing aluminum dihydroxychloride which comprisescontacting a solution of a salt of aluminum selected item the groupconsisting of aluminum chloride and aluminum hydroxydichloride with aweakly basic, water insoluble anion exchange resin and recovering theeflluent.

References Cited in the file of this patent Denk et aL: ChemicalAbstracts, vol. 47, page 3166(a) April 10, 1953.

Rohm and Haas Company, Washington Square, Philadelphia 5, Pa.advertisement Insoluble, Sodium, Hydroxide in company trade publicationof 1953.

Walton: Journal of Chemical Education, September 1946, page 455.

1. A METHOD OF PREPARING A HYDROXYL SUBSTITUTED BASIC ALUMINUM SALTWHICH COMPRISES CONTACTING A SOLUTION OF A SALT OF ALUMINUM WITH AWEAKLY BASIC, WATER INSOLUBLE ANION EXCHANGE RESIN IN THE HYDROXYL FORMAND RECOVERING THE EFFLUENT.